JP2014120380A5 - Power relay control device - Google Patents

Description

The present invention relates to a power supply relay control equipment for controlling the relay disposed between the actuator circuit for supplying power from a power source and the power source.

However, in the techniques described in Patent Documents 1 and 2, the ice generated at the relay contact is to be removed simply by repeating the ON / OFF operation of the relay or applying vibration. The ice may not be reliably removed.
Accordingly, the present invention has an object to provide a power supply relay control equipment which can appropriately prevent poor contact of the relay.

In order to solve the above-mentioned problem, a first aspect of a power relay control device according to the present invention controls a power relay circuit interposed between a battery and an actuator circuit to which power is supplied from the battery. a relay control unit, and the while outputting a relay-on command for the relay control unit to close the relay contacts of the power supply relay circuit, the abnormality detecting section for detecting a conduction abnormality between the relay contacts, the abnormality detecting unit And an abnormality processing unit that opens and closes the relay contact in a state where a predetermined potential difference is provided between the relay contacts when a conduction abnormality between the relay contacts is detected.

As a result, even if the contacts are close by the relay ON operation, even if an ice film exists between the relay contacts, the ice film is generated by the thermal energy of the arc between the contacts due to the potential difference between the relay contacts. Can be removed. Therefore, it is possible to easily ensure conduction between the relay contacts.
Further , a capacitor connected between the actuator circuit side contact of the power relay circuit and the ground, and a precharge circuit for charging the capacitor before closing the relay contact, the abnormality processing unit When the abnormality detection unit detects a continuity abnormality between the relay contacts, the amount of charge to the capacitor in the precharge circuit is determined as normal when the abnormality detection unit does not detect a continuity abnormality between the relay contacts. The relay contact is opened and closed in a state of being limited to a small amount as compared with the above.

Further, according to a second aspect , the abnormality detection unit is based on the amount of charge charged in the capacitor when the actuator circuit is driven in a state where the relay on command is output from the relay control unit. It is characterized by detecting a continuity abnormality between relay contacts.
As described above, when the actuator circuit is driven in a state where the relay contact is not conducted, the fact that the charge of the capacitor is lost is utilized, and therefore, the conduction abnormality between the relay contacts can be detected appropriately.

In the third aspect , the abnormality detection unit detects the voltage value at both ends of the capacitor as the amount of charge charged in the capacitor, and outputs the relay-on command from the relay control unit. When the voltage value when the actuator circuit is driven is equal to or less than an abnormal voltage threshold value, it is determined that a continuity abnormality has occurred between the relay contacts.
As described above, the voltage value at both ends of the capacitor when the actuator circuit is driven with the relay contact ON is compared with the preset abnormal voltage threshold value. Abnormalities can be detected.

Furthermore, the fourth aspect includes a temperature detection unit that detects a temperature in the vicinity of the relay contact, and the abnormality detection unit has a temperature detected by the temperature detection unit within the preset power relay circuit. When the temperature is equal to or lower than a low temperature environment determination temperature that is a temperature at which the possibility of icing is increased, a process for determining whether or not a conduction abnormality between the relay contacts has occurred is started .
As described above, when the power relay circuit is exposed to a low-temperature environment, it is determined whether or not there is a continuity abnormality between the relay contacts, thus preventing unnecessary continuity abnormality check of the relay contacts. be able to.

In the power relay control device of the present invention, the relay contacts are opened and closed with a predetermined potential difference between the relay contacts, so that arcing of the relay contacts can be induced to melt ice adhering to the relay contacts. Thus, the operation of the power supply relay in a low temperature environment can be ensured without using a special device .

The gate drive circuit 112 inputs the motor drive signal Ir and the motor rotational direction signal Ds outputted from the later-described MCU 101, a diagonal transistors Q1 and Q 4 or Q2 and Q 3 the drive controlling on the basis of these Thus, the electric motor 13 is rotationally driven according to the torque detection value T and the vehicle speed detection value Vs.
The power supply relay circuit 120 includes a normally-open relay contact 121 connected to the battery 15 and a relay coil 122 that opens and closes the relay contact 121. A surge absorbing diode 123 is connected to the relay coil 122 in parallel. One end of the relay coil 122 is connected to the battery 15 via an NPN transistor 124 as a switching element, and the other end is grounded.

Next, the configuration of the MCU 101 will be described.
The MCU 101 includes a watch dog timer (WDT) 102 that monitors its own program runaway. Further, the MCU 101 generates a motor drive signal Ir based on the detected torque value T, the detected vehicle speed value Vs, and the detected current value Im, and inputs this motor drive signal Ir to the motor drive circuit 110.

Therefore, in this embodiment, the relay ON / OFF operation is performed with a predetermined potential difference between the relay contacts for the purpose of removing the ice film existing between the relay contacts at the time of low temperature determination. The operation at this time will be described with reference to FIG.
First, the electrolytic capacitor 151 in the precharge circuit 150 is discharged, and then the precharge circuit 150 starts charging the electrolytic capacitor 151. When the VR voltage reaches the normal relay ON voltage VR1 at time t1, the relay contact 121 is turned on, and the charging of the electrolytic capacitor 151 by the precharge circuit 150 is terminated after the VR voltage reaches the precharge voltage VP. Next, at time t2, the motor drive circuit 110 is forcibly driven to check continuity. That is, a current necessary for power assist is supplied from the battery 15 to the H bridge circuit 111 via the power relay circuit 120.

Claims (4)

A battery, a relay control section for controlling the power relay circuit interposed between the actuator circuit power from the battery is supplied,
In a state in which a relay on command for closing the relay contact of the power relay circuit is output from the relay control unit, an abnormality detection unit that detects a conduction abnormality between the relay contacts;
When the abnormality detection unit detects a conduction abnormality between the relay contacts, an abnormality processing unit that opens and closes the relay contact with a predetermined potential difference between the relay contacts;
A capacitor connected between the actuator circuit side contact of the power relay circuit and ground;
A precharge circuit for charging the capacitor before closing the relay contact;
When the abnormality detection unit detects a conduction abnormality between the relay contacts by the abnormality detection unit, the abnormality detection unit indicates a charge amount to the capacitor in the precharge circuit, and a conduction abnormality between the relay contacts is detected by the abnormality detection unit. A power supply relay control device that opens and closes the relay contact in a state that is less restricted than in a normal state that is not detected . The abnormality detection unit detects a conduction abnormality between the relay contacts based on a charge amount charged in the capacitor when the actuator circuit is driven in a state where the relay on command is output from the relay control unit. The power supply relay control device according to claim 1 , wherein The abnormality detection unit detects the voltage value at both ends of the capacitor as the amount of charge charged in the capacitor, and drives the actuator circuit in a state where the relay control unit outputs the relay on command. The power relay control device according to claim 2 , wherein when the voltage value is equal to or less than an abnormal voltage threshold, it is determined that a continuity abnormality has occurred between the relay contacts. A temperature detector for detecting the temperature in the vicinity of the relay contact;
When the temperature detected by the temperature detection unit is equal to or lower than a preset low temperature environment determination temperature, which is a temperature at which the moisture inside the power relay circuit is likely to freeze , The power relay control device according to any one of claims 1 to 3 , wherein a process for determining whether or not a continuity abnormality is occurring is started .